/* vips_transpose3d
 *
 * 30/4/18
 * 	- from grid.c
 */

/*

	This file is part of VIPS.

	VIPS is free software; you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	02110-1301  USA

 */

/*

	These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <vips/vips.h>

#include "pconversion.h"

typedef struct _VipsTranspose3d {
	VipsConversion parent_instance;

	VipsImage *in;

	int page_height;

} VipsTranspose3d;

typedef VipsConversionClass VipsTranspose3dClass;

G_DEFINE_TYPE(VipsTranspose3d, vips_transpose3d, VIPS_TYPE_CONVERSION);

static int
vips_transpose3d_gen(VipsRegion *out_region,
	void *vseq, void *a, void *b, gboolean *stop)
{
	VipsRegion *ir = (VipsRegion *) vseq;
	VipsImage *in = (VipsImage *) a;
	VipsTranspose3d *transpose3d = (VipsTranspose3d *) b;
	VipsRect *r = &out_region->valid;

	int output_page_height = in->Ysize / transpose3d->page_height;

	int y;
	VipsRect tile;

	tile = *r;
	tile.height = 1;

	for (y = 0; y < r->height; y++) {
		/* y in output.
		 */
		int yo = r->top + y;

		/* On output page.
		 */
		int yop = yo / output_page_height;

		/* Line on output page.
		 */
		int yol = yo % output_page_height;

		/* y of input page.
		 */
		int yip = yol * transpose3d->page_height;

		/* y of input line.
		 */
		int yi = yip + yop;

		tile.top = yi;

		/* Render into out_region.
		 */
		if (vips_region_prepare_to(ir, out_region, &tile, tile.left, yo))
			return -1;
	}

	return 0;
}

static int
vips_transpose3d_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsConversion *conversion = VIPS_CONVERSION(object);
	VipsTranspose3d *transpose3d = (VipsTranspose3d *) object;

	VipsImage *in;

	if (VIPS_OBJECT_CLASS(vips_transpose3d_parent_class)->build(object))
		return -1;

	in = transpose3d->in;

	if (vips_check_coding_known(class->nickname, in) ||
		vips_image_pio_input(in))
		return -1;

	if (!vips_object_argument_isset(object, "page_height")) {
		if (vips_image_get_int(in,
				VIPS_META_PAGE_HEIGHT, &transpose3d->page_height)) // FIXME: Invalidates operation cache
			return -1;
	}

	if (transpose3d->page_height <= 0 ||
		in->Ysize % transpose3d->page_height != 0) {
		vips_error(class->nickname, "%s", _("bad page_height"));
		return -1;
	}

	if (vips_image_pipelinev(conversion->out,
			VIPS_DEMAND_STYLE_SMALLTILE, in, NULL))
		return -1;
	vips_image_set_int(conversion->out,
		VIPS_META_PAGE_HEIGHT, in->Ysize / transpose3d->page_height);

	if (vips_image_generate(conversion->out,
			vips_start_one, vips_transpose3d_gen, vips_stop_one,
			in, transpose3d))
		return -1;

	return 0;
}

static void
vips_transpose3d_class_init(VipsTranspose3dClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	vobject_class->nickname = "transpose3d";
	vobject_class->description = _("transpose3d an image");
	vobject_class->build = vips_transpose3d_build;

	VIPS_ARG_IMAGE(class, "in", 1,
		_("Input"),
		_("Input image"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsTranspose3d, in));

	VIPS_ARG_INT(class, "page_height", 3,
		_("Page height"),
		_("Height of each input page"),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET(VipsTranspose3d, page_height),
		0, 10000000, 0);
}

static void
vips_transpose3d_init(VipsTranspose3d *transpose3d)
{
}

/**
 * vips_transpose3d: (method)
 * @in: input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @page_height: %gint, size of each input page
 *
 * Transpose a volumetric image.
 *
 * Volumetric images are very tall, thin images, with the metadata item
 * #VIPS_META_PAGE_HEIGHT set to the height of each sub-image.
 *
 * This operation swaps the two major dimensions, so that page N in the
 * output contains the Nth scanline, in order, from each input page.
 *
 * You can override the #VIPS_META_PAGE_HEIGHT metadata item with the optional
 * @page_height parameter.
 *
 * #VIPS_META_PAGE_HEIGHT in the output image is the number of pages in the
 * input image.
 *
 * See also: vips_grid().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_transpose3d(VipsImage *in, VipsImage **out, ...)
{
	va_list ap;
	int result;

	va_start(ap, out);
	result = vips_call_split("transpose3d", ap, in, out);
	va_end(ap);

	return result;
}
